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Chockstone Forum - General Discussion

General Climbing Discussion

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6 areas in 6 weeks 30-Oct-2007 At 11:22:31 AM wombly

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Geologically, the entire sydney basin (read from nowra to the hunter valley, and west to lithgow) all recieved pretty much the same sequence of sediment when the material was first deposited, although there are some regional differences, particularly in the south.

The layer that is climbed most often in the blueys is the Banks wall sandstone - this includes shipley upper, the glen, piddo, zig zag, mt york and many more. It also makes up everything above the halfway ledge in the grose and the wolgan (read old baldy upper etc). The other big deposit that gets climbed is the burramoko sandstone - i.e. below the halfway ledge in the wolgan and the grose, shipley lower etc. The main difference between these two layers is the higher clay/feldspar content of the burramoko sandstone which makes it weather and decay more readily, which consequnely also means it is where most of the canyons form.

From what i've seen around the traps it seems that what happened after deposition of this material is also pretty important in a climbing sense, as it determines how well glued together (with either iron or silica) the grains have ended up.

As usual, I've ended up ranting without answering the question, but i guess that happens!